Who is Selling the Papers of John Quincy Dickinson?

In the last few years, at least two batches of John Quincy Dickinson materials have been sold at auction. In November 2002, Alex Autographs (www.alexautographs.com), an auction house in Cos Cob, Connecticut sold (i) Dickinson's September/October 1869 diary (the diary transcribed in the Congressional KKK Hearings Report), (ii) the two Fleishman affidavits written out by Dickinson and (iii) a personal letter from Charles Hamilton to Dickinson. Alex Autographs would not reveal any information about the seller, but did put me in touch with the buyer who was extremely helpful. Then in late 2004, HCA Auctions from North Carolina (hcaauctions.com) sold a number of Dickinson letters including both Civil War and Reconstruction material. HCA put me in touch with the buyer, the University of Vermont, but would provide no information about the seller's identity. I spoke to the curator of the Benson Historical Society, Mrs. Trutor, which has some Dickinson material. She knows some Dickinson family members in the area (JQD did not have any children) and did not believe that any of them had been selling documents. I really wonder who is selling this stuff and if there is more out there. Certainly the second batch was in possession of Dickinson's family at one point. After Dickinson's assasination, his brother went to Marianna and returned with a box of personal letters and the collection auctioned off includes condolence notes to Dickinson's parents.